Circular knitting machines



H. S. BURDETT CIRCULAR KNITTING MACHINES May 31, 1960 Filed Jan. 16, 1957 if F/GJ.

lab /6 5 Sheets-Sheet 1 May 31, 1960 H. s. BURDETT 2,938,364

CIRCULAR KNITTING MACHINES Filed Jan. 16, 1957 5 Sheets-Sheet 3 F/G.4 F/G.5. F/G-Z N63,, 4c CL 46 5 y 31, 1960 H. s. BURDETT 2,938,364

CIRCULAR KNITTING MACHINES Filed Jan. 16, 1957 5 Sheets-Sheet 4 May 31, 1960 H. s. BURDETT 2,938,364

CIRCULAR KNITTING MACHINES Filed Jan. 16, 1957 5 Sheets-Sheet 5 F/GQ.

Unite This invention relates to circular knitting machines,

and has reference particularly to circular latch needle machines of the superimposed needle cylinder type equipped with a plurality offeeders and jacquardpatterning mechanism; I 'j A machine of the superimposed needle cylinder type opposed top or rib needle cylinder, a circular series of double-ended latch needles for operation in said cylinders, needle-actuating sliders in both cylinders, and means for effecting, through the medium of the sliders, trans:

vice versa, in the production of rib or purl fabric or/ and fabric patterned by various links-links effects.

In this connection, the invention is primarily intended for application to double cylinder hose andhalf hose machines, although there is no limitation in this respect since it may also be applied to multi-feeder body machines of the superimposed needle cylinder type.

By jacquard patterning mechanism is meant needle selecting mechanism which operates to cause desired mm or plain cylinder, to take and knit a yarn supplied at any feeder whilst other needles at that feeder are caused to miss the said yarn. Thus, portions of 'a yarn taken and knitted by the desired needles at a feeder show on the front face of the fabric, whilst the portions of yarn missed by the said other needles at that feeder float at the back of the fabric. 3

. Now heretofore in a circular knitting machine of the kind concerned, Le. a superimposed cylinder machine S Pa in 7 2,938,364 Pat ntedMa 31,1969

- vide, in a circular knitting machine of the kind referred to, an improved system of selectively operating needles to miss yarns-ate feeder or feeders whereby, inter alia,

the aforementioned disadvantage is'overcome.

In thecase of ahose or half hose machine, the invention provides an additional advantage hereinafter to be described.

According to this invention, the jacquard patterning means are so; constructed and arranged that a needle which is, to miss a yarn supplied at apredetermined feeder during the production of jacquard effects is advanced, comprises a bottom or plain needle cyhnder, an'axially after the appropriae selecting point, to a position beyond clearing level so that the said yarn will extend in front of the stem of the needle below the open latch thereof. Hence, when the needle is ultimately retracted by the stitch cam at a subsequent-feeder, the aforesaid portion ference of needles from one cylinder to the other, and

of the yarn lying across the front of the needle will be cast over the needle hook without having entered the latter .suchwise as to become a straight unknitted portion of yarnat the back of the needle which portion does not appear on the faceiof the fabric.

equipped with two or more feeders and jacquard patterning mechanism, a needle which is to miss a'yarn sup plied at either or any of the feeders is not raised to clearing height at that feed; instead, the 'knitting butt of the=corresponding needle-actuating slider is caused to pass beneath the stitch cam at the feeder with the result that the needle is disposed at a sufficiently low level to prevent it from taking the yarn into its hook. As a consequence, the yarn is floated at the back of the needle.

This prior system of selectively operating needles to For simplicity of explanation in the following further description it will be assumed that the jacquard effects are produced, as iscu'stomary, on the bottomneedle cylinder, although this situation may bereversed so that such effects are produced on the to-pcylinder. needles working in one cylinder only, usually the bot- In carrying'outjthe invention, a selecting unit may con: veniently be provided immediately in advance of each feeder or each appropriate .feeder of the machine,.;a nd as a consequence of a selection of needles elfected by such a unit, those. sliders corresponding to needleswhich it is desired shall miss the yarn supplied at the adjoint ing feeder are caused to be raisedto such a height that their knitting buttsare elevated to a level above a feed cam preceding the stitch cam at the said feeder. sequently, needles selected to miss the yarn at thatfeeder pass by the latter without being retracted to knocking: over position, thus, in this convenient arrangement, means of any suitable character are provided for retractingthe sliders (and 'hence also the selected needles) to clearing height immediately after they have'passed the feeder so that the knitting butts of the said sliders will. then miss a yarn at a feeder whilst producing jacquard patterns :is not very satisfactory in cases where jacquard effects are to be combined with links-links patterning effects. Thus, for instance, to enable the transference of needles from the top cylinder to the bottom cylinder durneedle-actuating slidersare required to be raised to clearing height before they can receive needles from top sliders advanced by a top transfer carn at a transfer lo cation. But, heretofore, where bottom sliders were remg the production of links-links effects, the bottom 4 quired to be at the aforementioned low level to prevent the corresponding needles from'taking yarn supplied at any particular feeder in the production of jacquard effects, it was impossible for those same sliders to be previously elevated to clearing height at a transfer location immediately in advance of the said feeder for the purbe so disposed as to enable them to be acted 'upon, if required, by the feed cam andthe stitch cam at the bent feeder. Of course, if, as maybe, the'sliders'are elevate d again before reaching the next feeder, the corresponding needles will miss the yarn supplied thereat, and s6 din For retracting elevated sliders inQthis' manner "there may advantageously be provided between succeeding feeders, a levelling cam arranged for action upon con veniently disposed butts on the sliders. v [Howeven whilst the hereinbefore described improved system of selectively operating needles may be adopted at atleast the main feeder of a multi feeder circular ki'liif ting machine of the type concerned equipped with jac quard selector units, the arrangement of the machine may, if desired, be such that those needles which are caused to knit at the main feeder are automatically'disposed'at" a sufliciently low level, eig. reverse welt height, at at least one auxiliary feeder as to enable yarn supplied thereat to pass idly over the tops of the needle hooks. In this way': needles, caused "to -knit at the main. feeder are float'edi;

" g-passe;

through, iiefpreven'ted "from i taking yarn supplied at, the auxiliary feeder asa' consequence of which such yarn auxiliary Tfeeders. On the other traits, meedlesitjslecte'd to miss yarn at the main -feeder,by =virtde o beingadvanced to a position beyond-'clearing 'levl,-rnay aflyantageously be automatically levelled to clearing level 7 in advance or the first auxiliary feeder so that; =according to requirements, such needles can either b cause to knit at the 'first 'auxiliary feeder=and iloat' throufi the second auxiliary feeder, or he advancedagain jbeyon'd clearing level at the first auxiliary fe'eder suchwise as to miss yarn supplied thereat. In this second alternative, the needles which miss yarn at the first auxiliary feeder may be automatically levelled -to clearing levelin advance of'the second auriiliary feeder-and causedto knit at thclatter, p P l These results can be achieved even when a-s'electing unit is omitted at, say, the second auxiliary feeder, such omission providing more spacearoundthe-machine and simplifying theconstruction of-t-he same.

'As will be appreciated, the invention, inits extended form, enables the production of fabric incorporatin'gnot only floats resulting from-advancement of needles'to a position beyond clearing level'as'aforesaid, but also true float jacquard patterning eliects "producedrinthe' conven tional'manner. p

' In order that the invention may "hernore' clearly understood and readily carried into, practical-effect, a typical= example thereof applied to a three-feed'circnlarhose or half-hose machine of the superimposed rotary needle cylinder type will now be describedwith reference to the accompanying drawings, wherein, p Figure 1' is a fragmentary vertical sectional 'view through the 'knitting head of such machine,

Figure 2 is a dev eloped view of'thejtop and bottom can: system or the machine as seenffrom the insides of tli'ecamhoxes, r p l figures-3, 4, 5, Hand 7 are five views each depicting,

cams of the plain system S (Figure 2). Similarly surrounding-thetop needle-cylinder 3 is'a'top cam box or shell 8 carrying the cams of the rib system S.

The machine is provided with three feeds, viz. a main feeder F and two auxiliary feeders F and P In Figure 2, the cams at the main feeder F are divided in two-some at the right hand side and the remainder at the left-handmideof-thefignre. I?hus, so far as the plain cam system is concerned, the conventional triangular centre feed 'cam' at-the :niain-"feedep -F "is indicated at-9', whilst the1forward anti heel-ing stitch cams at opposite sides of the said centre feed cam, which is fixed, are

representedgatm and ll respectively. The plain stitch cams at the two auxiliary feeders F and F are shown at-I-Z respectively.- E'a'ch bf the two last mentioned cams is preceded by a feed cam 14 of the withdrawable bolt type; w

At a location U immediately in advance of the main feeder and alsoof the first auxiliary feeder there is provided a selector unit for producing jacquard effects. Alsoin advance of the. maini-feeder F at U there is a links-linksselector unit. It. is to be particularly noted that thereis no jacquard selector unit in advance of the second auxiliary feeder F Each of the bottom needle-actuating sliders 5 :isfurnished with three axiallyrspaced butts, viz. an upper .knitting butt 5a, a bottom additiona'lbutt 5b and an intermediate transfer butt Sc. 'The-knittingbutts 5a are so disposed transfercam .15. IArrangedimmediately beneathuand in inilongitudinal alignment, a double-ended needle, 2. hottomflslidenfirst and second intern1ediate jacks and a selecting jack, these instrumentsbeing' shown in different relative positions in the five views, and-.the'IIatter'Ibeing takenon the lines III-'III, IV--IV, V-.-'V,,and VI'VJ,

and-VII-gVII of Figure Zrespectively,

f Figure '8 isan elevational view illustrating, in a general way, the type of selector unit employed,

figure 9' is a vertical sectional view of such a .unit, igur'e'lO .is a detail plan view of the pawl and. ratchet gearing'of this selector unit, I Figure 11 is a fragmentary perspective yiew showing afe'w selected needlesraised to a positionbeyond clearinglevel ,to miss a yarn, and other needlesreceiving the same yarn to knit, it', at a feed, and

Figure 12 is a similar perspective view,.depictingneedies tajking a yarn toknit it and another needle retracted to asufiiciently low level. p "like parts are designated bysimil'arjreference char: acters throughout the drawings. "Referring to Figurel, it will be seen trated machine comprises a bottomor plainrotary needle cylinder 2, an axially .opposed top or ribrotary needle cylinder 3, 'doubleended latch needles 4. for operation in said cylinders, a set of bottom needle-actuating sliders 5 mounted .in the cylinder 2 beneath the needles-and .3 similar set of top needle-actuating sliders 6. provided ,in the cylinder 3. The two conventional sets .of slidersare for operating :theneedlesin the usual way for transferring thelsame from onecylinder to the other, according'to requirements. -.Surrounding :the bottom, needle cylinder Zis a -hottoni :cam box xor shell 7 titted with thesame-trick aseach of the (bottom sliders 5 ,thereis provided anaxially ;movable and comparatively shortsecond intermediate jack 16 the upper plain end -16 aof; which is .adapted-..for action on the IOWEIIHQSirfidfiiOf thesaiddsliderp A-t-.or near its lower end, each second intermediate jack 16- is provided wit-h a butt 1611,;and for..action on these :butts there-isincorporated-in a-lower extension 7a of the stationary bottom. cam .box 7, after each needle selecting unit at Uand U a jack raisingtcam 17 and an associated guard cam 18 arranged :above it followedimmediately by a jack depressing cam 19. -Im* mediately beneath. and in the'same trick 2a as. each second intermediatejack 16 there is a firstintermediate jack 20 of the swinging type. That is to say, the swinging (first intermediate) jacks 20 are arranged to rock about 200 of each swinging. jack 2 0 :is adapted "toiactton the that the .illusintermediate jack raising cam 17, a swinging jack raisin-g cam 22 and an associated guard cam 23 disposed above it..foilowed. -imn1ediately,by. a' cam 24 forv depressiuglele vatedxswinging jacks. The swinging jack raising cams 22 are, ofxcourse, for advancing selected jacks 20, and

the let-.clingv end ofcach of these cams is provided with a protruding portion 22b, b'elowand in advance ofthe operativeinclined edge'ZZaof the cam, which portion is chamfered .atan-acute angle with respect to 'theouter surface of the' adjoining needlecylinder Z for a purpose presentely tobe described. The face' of the guard-cam ZS above each swinging 'jack' raising earn 22 isrecessed at gasses-r "23a to permit outward projection of the upper ends of non-selected swinging jacks 20.

In longitudinal alignment with and below the swinging jacks 20 there are provided in the same tricks 2a, selecting jacks 25 having pre-arranged butts 25a of saw-tooth form (see Figures 3-7) adapted to be'acted upon selectively by banks of obliquely disposed superimposed selector slides 26-one bank to each selecting unit at U and U Initially, each selecting jack 25 is formed with a full complement of the saw-tooth butts 25a, although predetermined. ones of such butts on each jack 25 are broken away, according to patterning requirements.

- A little in advance of and below each bank of selector slides 26 there is provided, as illustratedin Figure 2, a presel'ector cam 27 of the bolt type which is movable into and out of operative position, under a suitable control, and is adapted, when operative, to act on tail butts 25b on the selecting jacks 25. A jack 25 before preselection is in a low position with its tail butt 25b at the level indicated at L in each of Figures 2 and 3. But, after being acted upon by an operative pre-selector cam the jack is elevated to the extent of the height of the said cam: thatis to say, the butt 25b is now at the level L (see Figure 4) and the upper end of the jack 25 instead of being separated from the swinging jack immediately above has been raised into contact with the lower end of the saidswinging jack. The pre-selector cams 27 are mounted on top of a sectional ring 28 arranged to embrace the lower ends of the selecting jacks as depicted in Figures 1 and 2. The bottom needle cylinder 2 is,'of course, extended downwardly to a greater extent than usual to accommodate the jacks =16, 20 and 25.-

The arrangement described and illustrated is accordingly such that whenever a pre-selected selecting jack 25 is lifted by an operative selector slide 26 at any one selecting unit at U or U the tail butt 25b of said jack will be elevated to the level L (Figure 5) and the corresponding first intermediate or swinging jack 20 will be raised from the position shown in Figure 4 to such a height as to land its butt 20b on to the relevant swinging jack raising cam 22. By the time the butt 20b lands on the cam 22, however, the pre-selected selecting jack 25, elevated by an operative selector slide 26, is already restored to its original low position by virtue of an upper butt 25a on the said selecting jack having been acted uponby a jack-depressor camportion29. Restoration of an elevated selecting'jack to its original low position in this manner takes place immediately in-advance of the next pre-selector cam 27. The cam 22 upon which the butt 20b has first been landed then functions to elevate the swinging jack 20 to' a higher level (see Figure 6) from which this jack is almost at once depressed to its original position by the relevant cam 24. Meanwhile, however, elevation of the swinging jack .20 pushes up the corresponding second intermediate jack 16 to a level at which its butt 16b is landed onto the'sec'ond intermediate jack raising cam 17. The said cam 17 further elevates the second intermediate jack 16 which, in'turn,'raises the bottom slider'S and hence also the corresponding needle 4, to the height required (see Figure 7). But, as previously mentioned, before this final stage of movement of the selected needle 4 is complete, the swinging jack 20, and

, also the selecting jack 25 immediatelybelow it, have been 4 of the needles (see Figures 7 and 11) in the production of jacquard patternsas aforesaid. In Figure 11 needles advanced to the height H are indicated at 4 Since the old loops on the needles are cleared from the latches 4a at a location immediately adjoining a feeder, the portions of yarn missed by the needles at that feeder will be cast over the closed hooks-together. with the said old loops at the next or at a subsequent'feeder, as the case may be: In any event, upon retraction of the needles at the appropriate feeder the open latches will be automatically closed thereby preventing the missed yarn from entering the hooks.

The height H above clearing lev'el CL necessitates axial needle movements of considerable extent which would, in the ordinary way, make it quite impossible for selecting jacks 25 elevated to the same extent to be depressed in time for 're-selection at thenext feed. Additionally, bottom sliders 5 may, in advance of the main feeder F be selected and elevated, through the medium of the relevant selecting and intermediate jacks, to a level at which the transfer butts 50 on the said' sliders are engaged by the conventional main'transfer bolt cam 15 for the purpose of initiating the transference of needles from the bottom cylinder to the top cylinder in the production of links-links efiects.

As will therefore be appreciated, it is readily possible, in the operation of a machine according to this invention, toeifect advancement" of sliders suchwise as to cause corresponding needles to'miss yarn at a-feeder which needles have, at an immediately preceding transfer station, been received by thesaid sliders from the opposed needle cylinder. Thus, considering bottom sliders 5 in the example' illustrated, if certain of these are raised to clear-" ing height at the transfer stationTS for the purpose of. receiving needles advanced from the top cylinder then all that has to -be done to ensure that these newly re: ceived needles shall-miss a yarn supplied at the immedi{ ately adjoining main feeder F is to elevate the sliders 5 a little higher than clearing height so that their knitting butts .5a will be disposed above the fixed feed cam 9 at the said feeder. As previously mentioned, the leading end of each swing-' ing'jack raising cam 22 is provided with a chamfered protruding portion 22b. The arrangement and formatiori of the portions 22b are such that the butts 20b of selected first intermediateor swinging jacks '20 initially advanced by the corresponding selecting jacks 25 at a feed will clear the relevant protruding chamfered'po rtion 22b and he landed on to the jack raising cam 22 at that feed, whereas the butts of non-selected jacks 20 (which are notadvanced) will be contacted and pressed back by the said chamfered portion suchwise' as to avoid being acted upon by the'raising cam 22. t

Asipreviously stated there is provided, at U in ad vance of the stitch and feed cams at each of the twofeeders'F and F a selector unit for producing jacquard effects and, at U in association'with the main feeder, also a'links-links selector unit. Bottom sliders 5 elevated in propriate needles to heeling height.

stages by the links-links unit'at U through the' medium of the various jacks, are disposed at such a height that their transfer butts 50 can be acted upon by the conven-' tional transfer bolt cam '15 in the bottom cam box.

The primary purpose of the lower additional butts 5b on the bottom sliders 5 is fully explained in the specification of my co-pending application Serial No. 634,532. The lower butts 5b are also acted upon by levelling cams 30 by which bottomsliders and hence also the corresponding needles are withdrawn to clearing level after having been selectively raised to a height above clearing level as aforesaid. At 31 is indicated a Vz-lift cam of the bolt type for action, when operative, upon thelower additional slider butts 5b for the purpose of raising ap- As shown in Figures 8,v 9 and 10, each selecting unit is advantageously of thev kind comprising a drum 32 furnished with pro-arranged pins 33 (or protuberant bits), and an associated bank of inclined slides 26, the drum beingintermittently rotatable, by a pawl and'ratchet mechanism 34, 35 (Figure 10) and the slides 26, en

.gagediand projectible by intermediate two-armed -;and spring'infiuenced selector levers 3.6 acted upon by the selecting jacks 25.

, -The clearingca-m 37 ,provided at the transfer, station TS in advance of the main feeder F is of the movable bolt type and, for'normalcircular knitting, istalways in its operative position. The bolt clearing cams 38 and 35? at the first auxiliary and second auxiliary feeders F and F respectively are-however, normally withdrawn and inoperative, this being the reason why such camsv are indicatedtin chain lines in Figure 2. Moreover, and as will, be appreciated :from a consideration of 1Figure2, there is no jacquard: selector unit in advance of .the ,second auxiliary feeder-.13

V jthisparticular,arrangemcntis accordingly 1 such that bottom slider knitting-butts a which are:acted upon and depressed by the'vstitchrcam ,10at the mainfeeder F can pass, without -,-first being raised to :clearing height, beneath the stitch ,cams 12 and 13. at the-fioat-inglevel FL (Figure 3) at the, first-and second xauxiliaryyfeeders ii nandF This level corresponds to reverse welt height.- As a consequenceneedles coupled to these particular sliders knit at .the ,main feeder-P anet merely float through both auxiliary feeders F and F i.e. pass by the, latter at .a sufficiently low level to prevent them taking yarn into .their books 40. .Theyarn ,(Y Figure 3) thus: missed by'the said needles is floated at the backsiof .the

same. In Figure 112, the-needle indicatedat 4 ,is shown -attthe said lowlevel where it missesthe: yarn Y whereas thisyarn has been takeninto the hooks of the needles ,4. On the other hand,;1 1ee. dles which are to ,knibat vthe feederlF are-raisedl tothe height H above clearing level CL at the main feeder, F i.e, those --needles coupled to sliders 5 the knitting bnttsSaof which pass, over the fixed centre feed cam 9 at the main 'feederi'F and thello'wer butts 5b of which are acted upon by the levelling cam 30 immediately in advaneeof thefirst auxiliaryfeeder F Thus, bya judicious selection of needles by' the selector unit in advance of the main feeder F it is possible to determine in an automatic fashion which needles are to knit, and which-are to miss yarn and permito'f theformation of conventionaljacquard patterning at the firstzauxiliary, feeder. F

Needles which are caused to knit at the first auxiliary feeder F arefioated through the second auxiliary feeder F in other words, the bottom slider knitting'butts "5a acted upon and depressed by the :stitch cam 12 automatically pass beneath the stitchcam 13 without having been -clevated to clearing height between. the said two' stitchcamsr l l r H Needles which knit at;the first auxiliary feeder F ,and are thus floatedthrough .the second auxiliary :feeder F as just described, vmay be and preferably are also caused to miss yarnat the main feeder F .by virtue of being raised at the. latter to theheight H above clearing level CL. For this purpose, selecting jacks 25 associated with 7 mal manner.

8. In thiscase-thelltnitting huttsja'rot the bottom sliders corresponding to such needles arecausedto pass over the topr-ofthe feed ,cam 14 precedingztheistitch.carn.

Since, as previously mentioned,the;clearingcam 37 is always in its operative position, during circularvknitting itfollows thattheknitting butts snot all of thebottom sliders '5 willbeacted upon by this camaspa consequence of which all of theneedles operating in the bottom cylinderwill be raised to clearing level ,CLfatthe transfer station .TS. It is whilst they are at clearing height that predetermined bottom sliders 5 receive needles advanced from, the top cylinderduring the production of links-links effects by a downward transfer of needles from the latter to the bottom cylinder. The improved arrangement therefore enables any needle which has only just been transferreddown from thetop cylinder attthe transfer station TSvto miss ,a yarnand produce a jacquard float effect at theimmediately adjoiningmain feeder F by virtue of the needle being advanced ,at-this feeder to the height H above the; clearing level CL at the dictates of the appropriateselectorunit. V

Sofar as the applicationofthe invention to .a; hose .or half hose machine is concerned, in which machine the bottom sliders are divided intotwo substantially semicircular groups, i.e. instepsliders with long butts, and heel and toe sliders with shorter butts, an additional advantage arising from the adoption of the invention is that the instep sliders can ,be raised to'heelingheight in the nor- Therefore, the conventional narrowing pickencan operate normally and without any additional mechanism to hold the picker down out of thegaps created in therseries of long butts by the-previously practised method of producing jacquard patterns.

I claim;

,1. A circular knitting machine'comprising, in combination, a bottom needle cylinder, anaxially ,opposedtop needle cylinder, double-ended latchneedles:operatingin said cylinders, .needleractuatingsliders inboth cylinders, each slider in said ,bottom cylinder-being furnished with an upper knitting butt, a lower butt and an intermediate transfer butt, a main feeder and at least one auxiliary feeder, each such feeder comprising means supplying yarn to needles anda-stitchcam preceded by a feed cam for action on the-upper knitting-butts for the purpose .of retracting the bottom sliders an'dhence also correspond ing needles and causingthe latter to take and knits-the supplied yarn, selecting jacks with apr-e-arranged,butts in the, bottom cylinder and bymeans ofwhich-thebottom slidersare selectively operated,,a seleetorun t for producing jacquard effects inadvanceof at leastithe main feeder, said unit including a bank-qof movable selector members; for action selectively upon the ;-pre-,arranged butts on the selectingjacks whereby desi ed needlessaid needles are pre-selectedbylhe cam 27 in" advance of the selecting unit immediately preceding-themain feeder as previously described herein.

Of course, by --appr,opriate :operation of the selector unit at the location U inadvance of the first auxiliary feeder F it ispossible to'cause needles which'have either knitted, or missed yarn, at :the main feeder F to be raised to the height; H above clearing level-CL at the feeder F fiwwith 'the result already described. 'Needles raised in this way to. the height H atthe first auxiliary fecder'F automatically; knit at the second anxiliary feede'r F because the lower butts 5b of -the bottorrisliderscortespondingto said needles are acted upon and depressed by the'lev'ellin'g cam 30 immediately in advanceofthe feeder F 5 "Thus, as will be understood,-the selecto'runit in ad vance of'the feeder F -can "housed in this .Way to determinewhich needles areto knit at the following feederF working ,in the bottom, cylinder take :andrknit yarn.supplied at-the maimfeeder whilst other-needles .in. the same cylinder are. caused to ;-miss said yarn,::theiarrangement being-such that as a: consequence'ofa selection of needles effected by saidunit th'ose 'bottomsliders corresponding to needlesrit is desiredshall-miss yarn-supplied at said mainfeeder are caused -to be elevated to sucha position beyond clearing-height that their knitt-ing--buttsare dis po'sed beyond and clear of the feed; cam preceding the stitchcam at the said feeder'whereby the-needles selected to miss the-yarn at that feeder pass by the latterwithout being acted upon by said feed and stitch cams, and, in athtanceof the selector unitassociated with the main feedena transfer station at which is 'locateda cam for action upon t-ransfer'butts offlbott om sliders, said-cam elevating bottom sliders toclcaringgheight for the purpose of receivingneedles advanced from thetopcylinder} whereby all, that isflfnecessa'ryrto ensure that. such newly received needles shall miss yarn.suppliedatQtheQmain feedei is to cause said selectorunit-to .elev. ate bottom sliders corresponding torsaidrnee dles a little higher than clearing height so that the knitting butts of the sliders will be disposed above the feed cam at the main feeder.

2. A circular knitting machine comprising, in combination, a bottom needle cylinder, an axially opposed top needle cylinder, double-ended latch needles operating in said cylinders, needle-actuating sliders furnished with knitting butts in both cylinders, means for effecting, through the medium of the sliders, transference of needles from one cylinder to the other, a main feeder and at least one auxiliary feeder, each such feeder including means for supplying yarn to needles and a stitch cam preceded by a feed cam for action on the knitting butts of the sliders working in one of the cylinders for the purpose of retracting said sliders and hence also corresponding needles and causing the latter to take and knit the supplied yarn, a selector unit for producing jacquard effects provided in advance of the main feeder, said unit effecting selective operation of the sliders working in the aforementioned cylinder suchwise as to enable desired needles to take and knit yarn supplied at the main feeder, whilst other needles at said feeder are caused to miss the said yarn, the arrangement being such that as a consequence of a selection of needles effected by said unit those sliders corresponding to needles it is desired shall miss yarn supplied at main feeder are caused to be advanced to such a position beyond clearing level that their knitting butts are disposed beyond and clear of the feed cam preceding the stitch cam at the main feeder whereby the needles selected to miss the yarn at that feeder pass by the latter without being acted upon by said feed and stitch cams, and means for retracting said advanced sliders to clearing height after they have passed by the main feeder so that the knitting butts of these same sliders are so disposed as to enable them to be acted upon by the feed and stitch cams at the auxiliary feeder, whereby needles which are caused to knit at the main feeder are automatically disposed at a sufiiciently low level at the auxiliary feeder as to enable yarn supplied thereat to pass idly over the needle hooks and form floats, whereas needles which are advanced to a position beyond clearing level at the main feeder are automatically retracted to clearing level in advance of the auxiliary feeder so as to enable them to knit at the latter.

3. A circular knitting machine comprising, in combination, a bottom needle cylinder, an axially opposed top needle cylinder, double-ended latch needles operating in said cylinders, needle-actuating sliders furnished with knitting butts in both cylinders, means for effecting, through the medium of the sliders, transference of needles from one cylinder to the other, a main feeder and first and second auxiliary feeders, each such feeder including means supplying yarn to needles and a stitch cam preceded by a feed cam for action on the knitting butts of the bottom sliders for the purpose of retracting said sliders and hence also corresponding needles and causing the latter to take and knit the supplied yarn, selecting jacks with prearranged butts in the bottom cylinder said jacks serving to operate the bottom sliders selectively, a first selector unit in advance of the main feeder, a second selector unit in advance of said first auxiliary feeder, each of said units including selector members for action selectively upon the pre-arranged butts on the selecting jacks whereby desired needles operating in the bottom cylinder take and knit yarn supplied at the relevant feeder whilst other needles in the same cylinder are caused to miss said yarn, the arrangement being such that as a consequence of a selection of needles effected by either of the selector units those bottom sliders corresponding to needles it is desired shall miss yarn supplied at the relevant feeder are caused to be elevated to such a position beyond clearing height that their knitting butts are disposed beyond and clear of the feed cam preceding the stitch cam at the said feeder whereby the said needles selected to miss the yarn at that feeder pass by the latter Without being acted upon by said feed and stitch cams, and levelling cams for automatically retracting said elevated bottom sliders to clearing height after they have passed by the relevant feeder and before they approach the next feeder whereby the knitting butts of these same sliders are so disposed as to enable them to be acted upon by the feed and stitch cams at the said next feeder, needles which are caused to knit at the main feeder being automatically disposed at a sufficiently low level at the first and second auxiliary feeders as to enable yarns supplied thereat to pass, without being knitted, over the tops of the needles and to form floats, whereas needles which are elevated by the first selector unit to a height beyond clearing level at the main feeder are retracted to clearing level in advance of the first auxiliary feeder and are thereby enabled to knit at the latter.

4. A circular knitting machine according to claim 3, wherein knitting butts of bottom sliders which are acted upon and depressed by the stitch cam at the main feeder are permitted to pass, without first being elevated to raise said sliders to clearing height, beneath the stitch cams at the first and second auxiliary feeders, for the purpose described.

5. A circular knitting machine according to claim 3, wherein selected bottom sliders the knitting butts of which pass over and clear of the feed cam at the main feeder are automatically retracted to clearing height by the levelling cam in advance of the first auxiliary feeder, and I the said knitting butts are thereupon acted upon and depressed by the feed and stitch cams at said first auxiliary feeder but are permitted to pass, without first being elevated to raise said sliders to clearing height, beneath the stitch cam at the second auxiliary feeder, for the purpose described.

6. A circular knitting machine according to claim 3,

wherein bottom sliders advanced beyond clearing height at the main feeder and subsequently retracted to such height in advance of the first auxiliary feeder are again advanced beyond clearing height by operation of the second selector unit in advance of the first auxiliary feeder but are then retracted to clearing height in advance of the second auxiliary feeder so that the knitting butts of the said sliders are acted upon and depressed by the feed and stitch cams at said second auxiliary feeder.

References Cited in the file of this patent UNITED STATES PATENTS 2,726,525 Haddad Dec. 13, 1955 2,780,931 Lawson et al Feb. 12, 1957 

